Molding unit



A. MARLO MOLDING UNIT March 30, 1965 2 Sheets-Sheet 1 Original Filed May26, 1959 INVENTOR: ARVID MARLO g%g;W;

ATT'YS March 30, 1965 A. MARLO 3,175,250

MOLDING UNIT Original Filed May 26, 1959 2 Sheets-Sheet 2 INVENTOR:ARVID MARLO BY M4406;

ATT'YS United States Patent 3,175,250 MOLDING UNIT Arvid Marlo, Chicago,Ill. {P.O. Box 38, Winnebago, Wis.)

Original application May 26, 1959, Ser. No. 815,974, new Patent No.3,048,896, dated Aug. 14, 1962. Divided and this application May 31,1962, Ser. No. 199,124

1 Claim. (Cl. 18-39) This invention relates in general to a moldingunit, and more particularly to a molding unit capable of molding hollowarticles, wherein the unit may be easily and quickly separated forfilling with a moldable material and for removal of a molded article.

It is therefore an object of this invention to provide an improvedmolding unit for molding a hollow article, wherein the mold is dividedinto sections that are resiliently biased together during the moldingoperation.

A further object of this invention resides in the provision of a moldingunit for molding a plurality of hollow articles, wherein the molds aredivided into sections which are resiliently biased together during themolding operation, and wherein the sections may be easily and quicklyseparated for purposes of filling the molds with a moldable material andfor removing the molded articles.

Other objects, features and advantages of the invention will be apparentfrom the following detailed disclosure, taken in conjunction with theaccompanying sheets of drawings, wherein like reference numerals referto like parts, in which:

FIG. 1 is a perspective view showing a molding unit according to thepresent invention and how it may be associated with a carriage or rackof a molding apparatus;

FIG. 2 is a perspective view of the molding unit of FIG. 1 andillustrating the locking bars removed and the molding unit in openposition;

FIG. 3 is an enlarged transverse sectional view of a mold, takensubstantially along line 3-3 of FIG. 1; and

FIG. 4 is an enlarged transverse sectional view taken through a modifiedmold according to the present invention.

Referring now to the drawings and particularly to FIG. 1, a rack orcarriage 28 of a molding apparatus is adapted to receive a molding unit29 according to the present invention. The rack 28 is mounted on a shaft26 extending through a wall 19 of an oven, and rotatably supported bymeans of a bearing member 25. The shaft extends outwardly of the bearingmember 25 as indicated by the numeral 27 and has mounted thereon apinion gear 36 that is adapted to be engaged by a rack gear (not showndriven to oscillate the carriage 28 as more clearly described in mycopending application Serial No. 815,974, filed May 26, 1959, now PatentNo. 3,048,896, granted August 14, 1962.

Each rack includes a solid back wall 30 having extending from the fourcorners thereof angle irons 31 which are rectangularly spaced andarranged to define an open framework for slidably receiving the moldingunit 29. The angle irons 31 extend parallel to each other andsubstantially perpendicular to the back wall 30. Flanges 32 projectsubstantially perpendicularly from the back wall 30 of each rack and arearranged between the angle irons 31 in order to reinforce the rackstructure.

Each molding unit 29 includes upper and lower mold supporting plates 48and 49, generally rectangular in shape, which may support therebetweenany number of molds desired. A plurality of molds 50 are carried by themold supporting plates 48 and 49. The molds 50 are sectional and areformed in halves which include 3,175,250 Patented Mar. 30, 1965 an uppersection 51 and a lower section 52 having internal surfaces shaped todefine a substantially oval shaped hollow article. It should beappreciated that the internal surface may be shaped to define anydesired shape of an article. The mating edges of the sections 51 and 52are complementally grooved, as indicated at 53, FIG. 3, to guide themating relation therebetween and provide a smooth inner wall surface forproducing seamless hollow plastic articles.

The lower mold section 52 is supported on the lower plate 49 by a stem54, which has a reduced portion 55 at its end thereby defining anannular shoulder 56. The reduced portion 55 is received in a blind bore57 provided in the lower plate 49, and the shoulder 56 bottoms againstthe upper surface of the plate 49 encircling the bore 57. A stud bolt 58fixedly secures the stem 54 to the plate 49, whereby the lower moldsection 52 is then fixedly mounted to the lower plate 49.

The upper mold section 51 is resiliently mounted on the upper moldsupporting plate 48 by means of a stem projecting from the upper end ofthe mold section and slidably received in a bore 60 extending throughthe upper plate. A coil spring 61 encircles the stem 59, and bottoms atone end on the top of the mold section 51 and at the other end on theunder surface of the upper plate 48 to resiliently bias the mold section51 downwardly and towards the lower mold section 52. A lock ring 62 isprovided to be secured to the upper end of the stem 59 and on the upperside of the plate 48 in a recessed portion 63 to limit the downwardmovement of the stem 59 from the plate 48.

Runners 64 are provided along the opposite edges of the upper plate 48on the upper side thereof, and runners 65 are provided along theopposite edges and on the lower side of the lower plate 49 in order toproperly size the molding unit for fit into the rack 28. If larger moldsare used than the molds 50, the size of the runners may be decreased inorder to still properly fit within the racks 28. On the other hand, ifthe mold size is decreased from that shown, the runner size can beincreased in order to fit in the racks 28. Thus, it may be appreciatedthat any size mold within certain limits may be utilized, and will bereceived within the racks 28 of the molding apparatus 17.

In order to lock the upper plate 48 with its mold sections 51 to thelower plate 4-9 with its mold sections 52, longitudinally extendinggrooves 65a are provided in the opposite edges of the upper plate 48,and longitudinally extending grooves 66 are provided in the oppositeedges of the lower plate 49 to receive flanges 67 of locking plates 63as seen in FIG. 3. The locking plates 68 are substantiallychannel-shaped and having the flanges 67 at the opposite edges extendingsubstantially perpendicularly to the main portion and for engagement inthe grooves of the upper and lower mold supporting plates. The distancebetween the flanges 67 is such that in order to engage them in thegrooves of the mold supporting plates, it is necessary to first pressthe mold supporting plates together against the biasing of the springs61, whereby when they are released, the flanges will frictionally lockwith the grooves, and thereby resiliently hold the mold sections 51 and52 together in proper mating position. Enlarged holes 69 are provided inthe locking plates 68 in order to permit circulation of air through themolding unit and around the molds 50. As set forth in my aforesaidcopending application, the molding units 29 are adapted to be set on acooling table, whereby air is circulated through the openings in thelocking plates 68 or through the opposite open ends of the molding unitin order to cool the molds prior to removal of the molded articles.

A modified type of molding unit, generally designated by the numeral29A, is shown in FIG. 4, which differs in the type of molds used andsupported between the upper and lower mold supporting plates 48 and 49.In this embodiment, the molds which may be designated by the numeral 50Aare not individually mounted to the supporting plates, but are joinedtogether by webbing 70 to define an upper sheet 71 of cavities 72 and alower sheet 73 of cavities 74, which mate together to define the moldsfor each of the hollow articles, as seen in FIG. 4. The lower sheet 73of cavities is fixed to the lower mold supporting plate 49 by aplurality of stems 75 extending downwardly from some of the cavities,and stud bolts 76, in a manner similar to that of the embodiment inFIGS. 1 to 3. Similarly, stems 77 extend upwardly from some of thecavities 72 of the upper sheet 71 and are slidably received in bores 78provided in the upper plate 48. Coil springs 79 are arranged between theupper plate and the mold cavities and locking rings 80 are provided toprevent the stems 77 from leaving the plate 48. Accordingly, the uppersheet 71 is resiliently mounted to the upper mold supporting plate 48.Therefore, the cavities 72 in the upper sheet 71 will mate with thecavities 74 in the lower sheet 73 when the upper and lower supportingplates 48 and 49 are placed together and the cavities will be biasedtoward each other in the same manner as in the embodiment of FIGS. 1 to3.

This application is a division of my copending application Serial No.815,974, filed May 26, 1959, now Patent No. 3,048,896, granted August14, 1962.

It will be understood that modifications and variations may be effectedwithout departing from the scope of the novel concepts of the presentinvention, but it is understood that this application is to be limitedonly by the scope of the appended claim.

The invention is hereby claimed as follows:

A molding unit comprising vertically spaced upper and lower moldcarrying plates having laterally extending opposed grooves in the sideedges thereof; a plurality of laterally spaced molds interposed betweenand carried by said plates, each of said molds including pairs ofopposed mating cavity members joined together by webbing to define anupper sheet of cavity members and a lower sheet of cavity members, thelower sheet of cavity members being secured to said lowerplate andselected ones of the cavity members carried by said upper sheet beingattached to said upper plate for vertical movement with respect'thereto;means biasing said sheets toward each other, and a pair of side plateshaving inturned edge flanges interfitting in the grooves in said moldcarrying plates to lock the latter together.

References Qited by the Examiner UNITED STATES PATENTS 2,298,057 10/42Kelm 1842 2,832,990 5/58 Miller 18-2 3,004,291 10/61 Schad 18-423,060,508 10/62 Duerksen 18-43 MICHAEL V. BRINDISI, Primary Examiner.

